Question

I’m working on My First ASP.NET Application. I have created some text boxes and buttons, and added client-side validation to the text boxes. I now wish to set and clear the enabled property of the buttons according to the contents and validity of the text boxes.

I have studied the questions and answers here, here, here and here, and the best I have been able to manage is this…

<script language="javascript" type="text/javascript">
    function SetButtonSensitivity()
    {
        var label = document.getElementById("<%= lblResult3.ClientID %>");
        var button = document.getElementById("<%= btnDone.ClientID %>");

        if (Page_ClientValidate())
        {
            label.Text = "valid";
            button.disabled = false;
        }
        else
        {
            label.Text = "not valid";
            button.disabled = true;
        }

    }
</script>

I can tell this script is invoked when I tab away from the textbox fields, as the error messages are emitted by the client-validate, but the script has no effect on the button or the label.

Can anyone see what I have overlooked?

Answer 1

You can’t acces the Text property of a label from javascript.
A label is rendered as a . You should try setting the innerHTML property:

label.innerHTML = "not valid";

Also use the javascript console to see what errors you have in your js code. (Ctrl+Shift+J in firefox)